This invention relates generally to self-checkout technologies, and more specifically to checking out using a mobile application. Shoppers fulfill orders at a physical retailer on behalf of customers, as part of an online shopping concierge service. Once a shopper has collected one or more items for purchase, the shopper must wait in line and purchase the items according to the traditional check-out process. This is a time-consuming process, and because shoppers use a mobile device to scan and record items each item picked up for purchase, involves redundant activity. A more efficient check-out process allows the shopper to complete purchase of selected items on his/her mobile device, thereby eliminating redundant actions and reducing the time required to fulfill an order.